The present invention relates generally to resin transfer molding, and more specifically to a method and apparatus for vacuum assisted resin transfer molding.
As an alternative to molding composite structures using a traditional autoclave, resin transfer molding processes are commonly used to mold fiber/resin composites by infusing a fiber preform with resin under a vacuum. To help achieve even distribution of resin throughout the preform and a predetermined thickness of the finished composite structure, some resin transfer molding processes, such as controlled atmospheric pressure resin infusion, utilize a half-atmosphere vacuum, while others, such as double bag vacuum infusion (DBVI), incorporate multiple vacuum bags. However, due to excess resin infused into the preform, known resin transfer molding processes typically produce finished composite structures that are consistently resin rich, have a high per ply thickness, and have a low fiber volume as compared to traditional autoclave-cured composite structures.